aboutsummaryrefslogtreecommitdiffstats
path: root/arch/x86/math-emu/reg_ld_str.c
blob: d597fe7423c98441f7ed52f8bcb0df3bd45646a9 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
/*---------------------------------------------------------------------------+
 |  reg_ld_str.c                                                             |
 |                                                                           |
 | All of the functions which transfer data between user memory and FPU_REGs.|
 |                                                                           |
 | Copyright (C) 1992,1993,1994,1996,1997                                    |
 |                  W. Metzenthen, 22 Parker St, Ormond, Vic 3163, Australia |
 |                  E-mail   billm@suburbia.net                              |
 |                                                                           |
 |                                                                           |
 +---------------------------------------------------------------------------*/

/*---------------------------------------------------------------------------+
 | Note:                                                                     |
 |    The file contains code which accesses user memory.                     |
 |    Emulator static data may change when user memory is accessed, due to   |
 |    other processes using the emulator while swapping is in progress.      |
 +---------------------------------------------------------------------------*/

#include "fpu_emu.h"

#include <asm/uaccess.h>

#include "fpu_system.h"
#include "exception.h"
#include "reg_constant.h"
#include "control_w.h"
#include "status_w.h"

#define DOUBLE_Emax 1023	/* largest valid exponent */
#define DOUBLE_Ebias 1023
#define DOUBLE_Emin (-1022)	/* smallest valid exponent */

#define SINGLE_Emax 127		/* largest valid exponent */
#define SINGLE_Ebias 127
#define SINGLE_Emin (-126)	/* smallest valid exponent */

static u_char normalize_no_excep(FPU_REG *r, int exp, int sign)
{
	u_char tag;

	setexponent16(r, exp);

	tag = FPU_normalize_nuo(r);
	stdexp(r);
	if (sign)
		setnegative(r);

	return tag;
}

int FPU_tagof(FPU_REG *ptr)
{
	int exp;

	exp = exponent16(ptr) & 0x7fff;
	if (exp == 0) {
		if (!(ptr->sigh | ptr->sigl)) {
			return TAG_Zero;
		}
		/* The number is a de-normal or pseudodenormal. */
		return TAG_Special;
	}

	if (exp == 0x7fff) {
		/* Is an Infinity, a NaN, or an unsupported data type. */
		return TAG_Special;
	}

	if (!(ptr->sigh & 0x80000000)) {
		/* Unsupported data type. */
		/* Valid numbers have the ms bit set to 1. */
		/* Unnormal. */
		return TAG_Special;
	}

	return TAG_Valid;
}

/* Get a long double from user memory */
int FPU_load_extended(long double __user *s, int stnr)
{
	FPU_REG *sti_ptr = &st(stnr);

	RE_ENTRANT_CHECK_OFF;
	FPU_access_ok(VERIFY_READ, s, 10);
	__copy_from_user(sti_ptr, s, 10);
	RE_ENTRANT_CHECK_ON;

	return FPU_tagof(sti_ptr);
}

/* Get a double from user memory */
int FPU_load_double(double __user *dfloat, FPU_REG *loaded_data)
{
	int exp, tag, negative;
	unsigned m64, l64;

	RE_ENTRANT_CHECK_OFF;
	FPU_access_ok(VERIFY_READ, dfloat, 8);
	FPU_get_user(m64, 1 + (unsigned long __user *)dfloat);
	FPU_get_user(l64, (unsigned long __user *)dfloat);
	RE_ENTRANT_CHECK_ON;

	negative = (m64 & 0x80000000) ? SIGN_Negative : SIGN_Positive;
	exp = ((m64 & 0x7ff00000) >> 20) - DOUBLE_Ebias + EXTENDED_Ebias;
	m64 &= 0xfffff;
	if (exp > DOUBLE_Emax + EXTENDED_Ebias) {
		/* Infinity or NaN */
		if ((m64 == 0) && (l64 == 0)) {
			/* +- infinity */
			loaded_data->sigh = 0x80000000;
			loaded_data->sigl = 0x00000000;
			exp = EXP_Infinity + EXTENDED_Ebias;
			tag = TAG_Special;
		} else {
			/* Must be a signaling or quiet NaN */
			exp = EXP_NaN + EXTENDED_Ebias;
			loaded_data->sigh = (m64 << 11) | 0x80000000;
			loaded_data->sigh |= l64 >> 21;
			loaded_data->sigl = l64 << 11;
			tag = TAG_Special;	/* The calling function must look for NaNs */
		}
	} else if (exp < DOUBLE_Emin + EXTENDED_Ebias) {
		/* Zero or de-normal */
		if ((m64 == 0) && (l64 == 0)) {
			/* Zero */
			reg_copy(&CONST_Z, loaded_data);
			exp = 0;
			tag = TAG_Zero;
		} else {
			/* De-normal */
			loaded_data->sigh = m64 << 11;
			loaded_data->sigh |= l64 >> 21;
			loaded_data->sigl = l64 << 11;

			return normalize_no_excep(loaded_data, DOUBLE_Emin,
						  negative)
			    | (denormal_operand() < 0 ? FPU_Exception : 0);
		}
	} else {
		loaded_data->sigh = (m64 << 11) | 0x80000000;
		loaded_data->sigh |= l64 >> 21;
		loaded_data->sigl = l64 << 11;

		tag = TAG_Valid;
	}

	setexponent16(loaded_data, exp | negative);

	return tag;
}

/* Get a float from user memory */
int FPU_load_single(float __user *single, FPU_REG *loaded_data)
{
	unsigned m32;
	int exp, tag, negative;

	RE_ENTRANT_CHECK_OFF;
	FPU_access_ok(VERIFY_READ, single, 4);
	FPU_get_user(m32, (unsigned long __user *)single);
	RE_ENTRANT_CHECK_ON;

	negative = (m32 & 0x80000000) ? SIGN_Negative : SIGN_Positive;

	if (!(m32 & 0x7fffffff)) {
		/* Zero */
		reg_copy(&CONST_Z, loaded_data);
		addexponent(loaded_data, negative);
		return TAG_Zero;
	}
	exp = ((m32 & 0x7f800000) >> 23) - SINGLE_Ebias + EXTENDED_Ebias;
	m32 = (m32 & 0x7fffff) << 8;
	if (exp < SINGLE_Emin + EXTENDED_Ebias) {
		/* De-normals */
		loaded_data->sigh = m32;
		loaded_data->sigl = 0;

		return normalize_no_excep(loaded_data, SINGLE_Emin, negative)
		    | (denormal_operand() < 0 ? FPU_Exception : 0);
	} else if (exp > SINGLE_Emax + EXTENDED_Ebias) {
		/* Infinity or NaN */
		if (m32 == 0) {
			/* +- infinity */
			loaded_data->sigh = 0x80000000;
			loaded_data->sigl = 0x00000000;
			exp = EXP_Infinity + EXTENDED_Ebias;
			tag = TAG_Special;
		} else {
			/* Must be a signaling or quiet NaN */
			exp = EXP_NaN + EXTENDED_Ebias;
			loaded_data->sigh = m32 | 0x80000000;
			loaded_data->sigl = 0;
			tag = TAG_Special;	/* The calling function must look for NaNs */
		}
	} else {
		loaded_data->sigh = m32 | 0x80000000;
		loaded_data->sigl = 0;
		tag = TAG_Valid;
	}

	setexponent16(loaded_data, exp | negative);	/* Set the sign. */

	return tag;
}

/* Get a long long from user memory */
int FPU_load_int64(long long __user *_s)
{
	long long s;
	int sign;
	FPU_REG *st0_ptr = &st(0);

	RE_ENTRANT_CHECK_OFF;
	FPU_access_ok(VERIFY_READ, _s, 8);
	if (copy_from_user(&s, _s, 8))
		FPU_abort;
	RE_ENTRANT_CHECK_ON;

	if (s == 0) {
		reg_copy(&CONST_Z, st0_ptr);
		return TAG_Zero;
	}

	if (s > 0)
		sign = SIGN_Positive;
	else {
		s = -s;
		sign = SIGN_Negative;
	}

	significand(st0_ptr) = s;

	return normalize_no_excep(st0_ptr, 63, sign);
}

/* Get a long from user memory */
int FPU_load_int32(long __user *_s, FPU_REG *loaded_data)
{
	long s;
	int negative;

	RE_ENTRANT_CHECK_OFF;
	FPU_access_ok(VERIFY_READ, _s, 4);
	FPU_get_user(s, _s);
	RE_ENTRANT_CHECK_ON;

	if (s == 0) {
		reg_copy(&CONST_Z, loaded_data);
		return TAG_Zero;
	}

	if (s > 0)
		negative = SIGN_Positive;
	else {
		s = -s;
		negative = SIGN_Negative;
	}

	loaded_data->sigh = s;
	loaded_data->sigl = 0;

	return normalize_no_excep(loaded_data, 31, negative);
}

/* Get a short from user memory */
int FPU_load_int16(short __user *_s, FPU_REG *loaded_data)
{
	int s, negative;

	RE_ENTRANT_CHECK_OFF;
	FPU_access_ok(VERIFY_READ, _s, 2);
	/* Cast as short to get the sign extended. */
	FPU_get_user(s, _s);
	RE_ENTRANT_CHECK_ON;

	if (s == 0) {
		reg_copy(&CONST_Z, loaded_data);
		return TAG_Zero;
	}

	if (s > 0)
		negative = SIGN_Positive;
	else {
		s = -s;
		negative = SIGN_Negative;
	}

	loaded_data->sigh = s << 16;
	loaded_data->sigl = 0;

	return normalize_no_excep(loaded_data, 15, negative);
}

/* Get a packed bcd array from user memory */
int FPU_load_bcd(u_char __user *s)
{
	FPU_REG *st0_ptr = &st(0);
	int pos;
	u_char bcd;
	long long l = 0;
	int sign;

	RE_ENTRANT_CHECK_OFF;
	FPU_access_ok(VERIFY_READ, s, 10);
	RE_ENTRANT_CHECK_ON;
	for (pos = 8; pos >= 0; pos--) {
		l *= 10;
		RE_ENTRANT_CHECK_OFF;
		FPU_get_user(bcd, s + pos);
		RE_ENTRANT_CHECK_ON;
		l += bcd >> 4;
		l *= 10;
		l += bcd & 0x0f;
	}

	RE_ENTRANT_CHECK_OFF;
	FPU_get_user(sign, s + 9);
	sign = sign & 0x80 ? SIGN_Negative : SIGN_Positive;
	RE_ENTRANT_CHECK_ON;

	if (l == 0) {
		reg_copy(&CONST_Z, st0_ptr);
		addexponent(st0_ptr, sign);	/* Set the sign. */
		return TAG_Zero;
	} else {
		significand(st0_ptr) = l;
		return normalize_no_excep(st0_ptr, 63, sign);
	}
}

/*===========================================================================*/

/* Put a long double into user memory */
int FPU_store_extended(FPU_REG *st0_ptr, u_char st0_tag,
		       long double __user * d)
{
	/*
	   The only exception raised by an attempt to store to an
	   extended format is the Invalid Stack exception, i.e.
	   attempting to store from an empty register.
	 */

	if (st0_tag != TAG_Empty) {
		RE_ENTRANT_CHECK_OFF;
		FPU_access_ok(VERIFY_WRITE, d, 10);

		FPU_put_user(st0_ptr->sigl, (unsigned long __user *)d);
		FPU_put_user(st0_ptr->sigh,
			     (unsigned long __user *)((u_char __user *) d + 4));
		FPU_put_user(exponent16(st0_ptr),
			     (unsigned short __user *)((u_char __user *) d +
						       8));
		RE_ENTRANT_CHECK_ON;

		return 1;
	}

	/* Empty register (stack underflow) */
	EXCEPTION(EX_StackUnder);
	if (control_word & CW_Invalid) {
		/* The masked response */
		/* Put out the QNaN indefinite */
		RE_ENTRANT_CHECK_OFF;
		FPU_access_ok(VERIFY_WRITE, d, 10);
		FPU_put_user(0, (unsigned long __user *)d);
		FPU_put_user(0xc0000000, 1 + (unsigned long __user *)d);
		FPU_put_user(0xffff, 4 + (short __user *)d);
		RE_ENTRANT_CHECK_ON;
		return 1;
	} else
		return 0;

}

/* Put a double into user memory */
int FPU_store_double(FPU_REG *st0_ptr, u_char st0_tag, double __user *dfloat)
{
	unsigned long l[2];
	unsigned long increment = 0;	/* avoid gcc warnings */
	int precision_loss;
	int exp;
	FPU_REG tmp;

	l[0] = 0;
	l[1] = 0;
	if (st0_tag == TAG_Valid) {
		reg_copy(st0_ptr, &tmp);
		exp = exponent(&tmp);

		if (exp < DOUBLE_Emin) {	/* It may be a denormal */
			addexponent(&tmp, -DOUBLE_Emin + 52);	/* largest exp to be 51 */
denormal_arg:
			if ((precision_loss = FPU_round_to_int(&tmp, st0_tag))) {
#ifdef PECULIAR_486
				/* Did it round to a non-denormal ? */
				/* This behaviour might be regarded as peculiar, it appears
				   that the 80486 rounds to the dest precision, then
				   converts to decide underflow. */
				if (!
				    ((tmp.sigh == 0x00100000) && (tmp.sigl == 0)
				     && (st0_ptr->sigl & 0x000007ff)))
#endif /* PECULIAR_486 */
				{
					EXCEPTION(EX_Underflow);
					/* This is a special case: see sec 16.2.5.1 of
					   the 80486 book */
					if (!(control_word & CW_Underflow))
						return 0;
				}
				EXCEPTION(precision_loss);
				if (!(control_word & CW_Precision))
					return 0;
			}
			l[0] = tmp.sigl;
			l[1] = tmp.sigh;
		} else {
			if (tmp.sigl & 0x000007ff) {
				precision_loss = 1;
				switch (control_word & CW_RC) {
				case RC_RND:
					/* Rounding can get a little messy.. */
					increment = ((tmp.sigl & 0x7ff) > 0x400) |	/* nearest */
					    ((tmp.sigl & 0xc00) == 0xc00);	/* odd -> even */
					break;
				case RC_DOWN:	/* towards -infinity */
					increment =
					    signpositive(&tmp) ? 0 : tmp.
					    sigl & 0x7ff;
					break;
				case RC_UP:	/* towards +infinity */
					increment =
					    signpositive(&tmp) ? tmp.
					    sigl & 0x7ff : 0;
					break;
				case RC_CHOP:
					increment = 0;
					break;
				}

				/* Truncate the mantissa */
				tmp.sigl &= 0xfffff800;

				if (increment) {
					if (tmp.sigl >= 0xfffff800) {
						/* the sigl part overflows */
						if (tmp.sigh == 0xffffffff) {
							/* The sigh part overflows */
							tmp.sigh = 0x80000000;
							exp++;
							if (exp >= EXP_OVER)
								goto overflow;
						} else {
							tmp.sigh++;
						}
						tmp.sigl = 0x00000000;
					} else {
						/* We only need to increment sigl */
						tmp.sigl += 0x00000800;
					}
				}
			} else
				precision_loss = 0;

			l[0] = (tmp.sigl >> 11) | (tmp.sigh << 21);
			l[1] = ((tmp.sigh >> 11) & 0xfffff);

			if (exp > DOUBLE_Emax) {
			      overflow:
				EXCEPTION(EX_Overflow);
				if (!(control_word & CW_Overflow))
					return 0;
				set_precision_flag_up();
				if (!(control_word & CW_Precision))
					return 0;

				/* This is a special case: see sec 16.2.5.1 of the 80486 book */
				/* Overflow to infinity */
				l[1] = 0x7ff00000;	/* Set to + INF */
			} else {
				if (precision_loss) {
					if (increment)
						set_precision_flag_up();
					else
						set_precision_flag_down();
				}
				/* Add the exponent */
				l[1] |= (((exp + DOUBLE_Ebias) & 0x7ff) << 20);
			}
		}
	} else if (st0_tag == TAG_Zero) {
		/* Number is zero */
	} else if (st0_tag == TAG_Special) {
		st0_tag = FPU_Special(st0_ptr);
		if (st0_tag == TW_Denormal) {
			/* A denormal will always underflow. */
#ifndef PECULIAR_486
			/* An 80486 is supposed to be able to generate
			   a denormal exception here, but... */
			/* Underflow has priority. */
			if (control_word & CW_Underflow)
				denormal_operand();
#endif /* PECULIAR_486 */
			reg_copy(st0_ptr, &tmp);
			goto denormal_arg;
		} else if (st0_tag == TW_Infinity) {
			l[1] = 0x7ff00000;
		} else if (st0_tag == TW_NaN) {
			/* Is it really a NaN ? */
			if ((exponent(st0_ptr) == EXP_OVER)
			    && (st0_ptr->sigh & 0x80000000)) {
				/* See if we can get a valid NaN from the FPU_REG */
				l[0] =
				    (st0_ptr->sigl >> 11) | (st0_ptr->
							     sigh << 21);
				l[1] = ((st0_ptr->sigh >> 11) & 0xfffff);
				if (!(st0_ptr->sigh & 0x40000000)) {
					/* It is a signalling NaN */
					EXCEPTION(EX_Invalid);
					if (!(control_word & CW_Invalid))
						return 0;
					l[1] |= (0x40000000 >> 11);
				}
				l[1] |= 0x7ff00000;
			} else {
				/* It is an unsupported data type */
				EXCEPTION(EX_Invalid);
				if (!(control_word & CW_Invalid))
					return 0;
				l[1] = 0xfff80000;
			}
		}
	} else if (st0_tag == TAG_Empty) {
		/* Empty register (stack underflow) */
		EXCEPTION(EX_StackUnder);
		if (control_word & CW_Invalid) {
			/* The masked response */
			/* Put out the QNaN indefinite */
			RE_ENTRANT_CHECK_OFF;
			FPU_access_ok(VERIFY_WRITE, dfloat, 8);
			FPU_put_user(0, (unsigned long __user *)dfloat);
			FPU_put_user(0xfff80000,
				     1 + (unsigned long __user *)dfloat);
			RE_ENTRANT_CHECK_ON;
			return 1;
		} else
			return 0;
	}
	if (getsign(st0_ptr))
		l[1] |= 0x80000000;

	RE_ENTRANT_CHECK_OFF;
	FPU_access_ok(VERIFY_WRITE, dfloat, 8);
	FPU_put_user(l[0], (unsigned long __user *)dfloat);
	FPU_put_user(l[1], 1 + (unsigned long __user *)dfloat);
	RE_ENTRANT_CHECK_ON;

	return 1;
}

/* Put a float into user memory */
int FPU_store_single(FPU_REG *st0_ptr, u_char st0_tag, float __user *single)
{
	long templ = 0;
	unsigned long increment = 0;	/* avoid gcc warnings */
	int precision_loss;
	int exp;
	FPU_REG tmp;

	if (st0_tag == TAG_Valid) {

		reg_copy(st0_ptr, &tmp);
		exp = exponent(&tmp);

		if (exp < SINGLE_Emin) {
			addexponent(&tmp, -SINGLE_Emin + 23);	/* largest exp to be 22 */

		      denormal_arg:

			if ((precision_loss = FPU_round_to_int(&tmp, st0_tag))) {
#ifdef PECULIAR_486
				/* Did it round to a non-denormal ? */
				/* This behaviour might be regarded as peculiar, it appears
				   that the 80486 rounds to the dest precision, then
				   converts to decide underflow. */
				if (!((tmp.sigl == 0x00800000) &&
				      ((st0_ptr->sigh & 0x000000ff)
				       || st0_ptr->sigl)))
#endif /* PECULIAR_486 */
				{
					EXCEPTION(EX_Underflow);
					/* This is a special case: see sec 16.2.5.1 of
					   the 80486 book */
					if (!(control_word & CW_Underflow))
						return 0;
				}
				EXCEPTION(precision_loss);
				if (!(control_word & CW_Precision))
					return 0;
			}
			templ = tmp.sigl;
		} else {
			if (tmp.sigl | (tmp.sigh & 0x000000ff)) {
				unsigned long sigh = tmp.sigh;
				unsigned long sigl = tmp.sigl;

				precision_loss = 1;
				switch (control_word & CW_RC) {
				case RC_RND:
					increment = ((sigh & 0xff) > 0x80)	/* more than half */
					    ||(((sigh & 0xff) == 0x80) && sigl)	/* more than half */
					    ||((sigh & 0x180) == 0x180);	/* round to even */
					break;
				case RC_DOWN:	/* towards -infinity */
					increment = signpositive(&tmp)
					    ? 0 : (sigl | (sigh & 0xff));
					break;
				case RC_UP:	/* towards +infinity */
					increment = signpositive(&tmp)
					    ? (sigl | (sigh & 0xff)) : 0;
					break;
				case RC_CHOP:
					increment = 0;
					break;
				}

				/* Truncate part of the mantissa */
				tmp.sigl = 0;

				if (increment) {
					if (sigh >= 0xffffff00) {
						/* The sigh part overflows */
						tmp.sigh = 0x80000000;
						exp++;
						if (exp >= EXP_OVER)
							goto overflow;
					} else {
						tmp.sigh &= 0xffffff00;
						tmp.sigh += 0x100;
					}
				} else {
					tmp.sigh &= 0xffffff00;	/* Finish the truncation */
				}
			} else
				precision_loss = 0;

			templ = (tmp.sigh >> 8) & 0x007fffff;

			if (exp > SINGLE_Emax) {
			      overflow:
				EXCEPTION(EX_Overflow);
				if (!(control_word & CW_Overflow))
					return 0;
				set_precision_flag_up();
				if (!(control_word & CW_Precision))
					return 0;

				/* This is a special case: see sec 16.2.5.1 of the 80486 book. */
				/* Masked response is overflow to infinity. */
				templ = 0x7f800000;
			} else {
				if (precision_loss) {
					if (increment)
						set_precision_flag_up();
					else
						set_precision_flag_down();
				}
				/* Add the exponent */
				templ |= ((exp + SINGLE_Ebias) & 0xff) << 23;
			}
		}
	} else if (st0_tag == TAG_Zero) {
		templ = 0;
	} else if (st0_tag == TAG_Special) {
		st0_tag = FPU_Special(st0_ptr);
		if (st0_tag == TW_Denormal) {
			reg_copy(st0_ptr, &tmp);

			/* A denormal will always underflow. */
#ifndef PECULIAR_486
			/* An 80486 is supposed to be able to generate
			   a denormal exception here, but... */
			/* Underflow has priority. */
			if (control_word & CW_Underflow)
				denormal_operand();
#endif /* PECULIAR_486 */
			goto denormal_arg;
		} else if (st0_tag == TW_Infinity) {
			templ = 0x7f800000;
		} else if (st0_tag == TW_NaN) {
			/* Is it really a NaN ? */
			if ((exponent(st0_ptr) == EXP_OVER)
			    && (st0_ptr->sigh & 0x80000000)) {
				/* See if we can get a valid NaN from the FPU_REG */
				templ = st0_ptr->sigh >> 8;
				if (!(st0_ptr->sigh & 0x40000000)) {
					/* It is a signalling NaN */
					EXCEPTION(EX_Invalid);
					if (!(control_word & CW_Invalid))
						return 0;
					templ |= (0x40000000 >> 8);
				}
				templ |= 0x7f800000;
			} else {
				/* It is an unsupported data type */
				EXCEPTION(EX_Invalid);
				if (!(control_word & CW_Invalid))
					return 0;
				templ = 0xffc00000;
			}
		}
#ifdef PARANOID
		else {
			EXCEPTION(EX_INTERNAL | 0x164);
			return 0;
		}
#endif
	} else if (st0_tag == TAG_Empty) {
		/* Empty register (stack underflow) */
		EXCEPTION(EX_StackUnder);
		if (control_word & EX_Invalid) {
			/* The masked response */
			/* Put out the QNaN indefinite */
			RE_ENTRANT_CHECK_OFF;
			FPU_access_ok(VERIFY_WRITE, single, 4);
			FPU_put_user(0xffc00000,
				     (unsigned long __user *)single);
			RE_ENTRANT_CHECK_ON;
			return 1;
		} else
			return 0;
	}
#ifdef PARANOID
	else {
		EXCEPTION(EX_INTERNAL | 0x163);
		return 0;
	}
#endif
	if (getsign(st0_ptr))
		templ |= 0x80000000;

	RE_ENTRANT_CHECK_OFF;
	FPU_access_ok(VERIFY_WRITE, single, 4);
	FPU_put_user(templ, (unsigned long __user *)single);
	RE_ENTRANT_CHECK_ON;

	return 1;
}

/* Put a long long into user memory */
int FPU_store_int64(FPU_REG *st0_ptr, u_char st0_tag, long long __user *d)
{
	FPU_REG t;
	long long tll;
	int precision_loss;

	if (st0_tag == TAG_Empty) {
		/* Empty register (stack underflow) */
		EXCEPTION(EX_StackUnder);
		goto invalid_operand;
	} else if (st0_tag == TAG_Special) {
		st0_tag = FPU_Special(st0_ptr);
		if ((st0_tag == TW_Infinity) || (st0_tag == TW_NaN)) {
			EXCEPTION(EX_Invalid);
			goto invalid_operand;
		}
	}

	reg_copy(st0_ptr, &t);
	precision_loss = FPU_round_to_int(&t, st0_tag);
	((long *)&tll)[0] = t.sigl;
	((long *)&tll)[1] = t.sigh;
	if ((precision_loss == 1) ||
	    ((t.sigh & 0x80000000) &&
	     !((t.sigh == 0x80000000) && (t.sigl == 0) && signnegative(&t)))) {
		EXCEPTION(EX_Invalid);
		/* This is a special case: see sec 16.2.5.1 of the 80486 book */
	      invalid_operand:
		if (control_word & EX_Invalid) {
			/* Produce something like QNaN "indefinite" */
			tll = 0x8000000000000000LL;
		} else
			return 0;
	} else {
		if (precision_loss)
			set_precision_flag(precision_loss);
		if (signnegative(&t))
			tll = -tll;
	}

	RE_ENTRANT_CHECK_OFF;
	FPU_access_ok(VERIFY_WRITE, d, 8);
	if (copy_to_user(d, &tll, 8))
		FPU_abort;
	RE_ENTRANT_CHECK_ON;

	return 1;
}

/* Put a long into user memory */
int FPU_store_int32(FPU_REG *st0_ptr, u_char st0_tag, long __user *d)
{
	FPU_REG t;
	int precision_loss;

	if (st0_tag == TAG_Empty) {
		/* Empty register (stack underflow) */
		EXCEPTION(EX_StackUnder);
		goto invalid_operand;
	} else if (st0_tag == TAG_Special) {
		st0_tag = FPU_Special(st0_ptr);
		if ((st0_tag == TW_Infinity) || (st0_tag == TW_NaN)) {
			EXCEPTION(EX_Invalid);
			goto invalid_operand;
		}
	}

	reg_copy(st0_ptr, &t);
	precision_loss = FPU_round_to_int(&t, st0_tag);
	if (t.sigh ||
	    ((t.sigl & 0x80000000) &&
	     !((t.sigl == 0x80000000) && signnegative(&t)))) {
		EXCEPTION(EX_Invalid);
		/* This is a special case: see sec 16.2.5.1 of the 80486 book */
	      invalid_operand:
		if (control_word & EX_Invalid) {
			/* Produce something like QNaN "indefinite" */
			t.sigl = 0x80000000;
		} else
			return 0;
	} else {
		if (precision_loss)
			set_precision_flag(precision_loss);
		if (signnegative(&t))
			t.sigl = -(long)t.sigl;
	}

	RE_ENTRANT_CHECK_OFF;
	FPU_access_ok(VERIFY_WRITE, d, 4);
	FPU_put_user(t.sigl, (unsigned long __user *)d);
	RE_ENTRANT_CHECK_ON;

	return 1;
}

/* Put a short into user memory */
int FPU_store_int16(FPU_REG *st0_ptr, u_char st0_tag, short __user *d)
{
	FPU_REG t;
	int precision_loss;

	if (st0_tag == TAG_Empty) {
		/* Empty register (stack underflow) */
		EXCEPTION(EX_StackUnder);
		goto invalid_operand;
	} else if (st0_tag == TAG_Special) {
		st0_tag = FPU_Special(st0_ptr);
		if ((st0_tag == TW_Infinity) || (st0_tag == TW_NaN)) {
			EXCEPTION(EX_Invalid);
			goto invalid_operand;
		}
	}

	reg_copy(st0_ptr, &t);
	precision_loss = FPU_round_to_int(&t, st0_tag);
	if (t.sigh ||
	    ((t.sigl & 0xffff8000) &&
	     !((t.sigl == 0x8000) && signnegative(&t)))) {
		EXCEPTION(EX_Invalid);
		/* This is a special case: see sec 16.2.5.1 of the 80486 book */
	      invalid_operand:
		if (control_word & EX_Invalid) {
			/* Produce something like QNaN "indefinite" */
			t.sigl = 0x8000;
		} else
			return 0;
	} else {
		if (precision_loss)
			set_precision_flag(precision_loss);
		if (signnegative(&t))
			t.sigl = -t.sigl;
	}

	RE_ENTRANT_CHECK_OFF;
	FPU_access_ok(VERIFY_WRITE, d, 2);
	FPU_put_user((short)t.sigl, d);
	RE_ENTRANT_CHECK_ON;

	return 1;
}

/* Put a packed bcd array into user memory */
int FPU_store_bcd(FPU_REG *st0_ptr, u_char st0_tag, u_char __user *d)
{
	FPU_REG t;
	unsigned long long ll;
	u_char b;
	int i, precision_loss;
	u_char sign = (getsign(st0_ptr) == SIGN_NEG) ? 0x80 : 0;

	if (st0_tag == TAG_Empty) {
		/* Empty register (stack underflow) */
		EXCEPTION(EX_StackUnder);
		goto invalid_operand;
	} else if (st0_tag == TAG_Special) {
		st0_tag = FPU_Special(st0_ptr);
		if ((st0_tag == TW_Infinity) || (st0_tag == TW_NaN)) {
			EXCEPTION(EX_Invalid);
			goto invalid_operand;
		}
	}

	reg_copy(st0_ptr, &t);
	precision_loss = FPU_round_to_int(&t, st0_tag);
	ll = significand(&t);

	/* Check for overflow, by comparing with 999999999999999999 decimal. */
	if ((t.sigh > 0x0de0b6b3) ||
	    ((t.sigh == 0x0de0b6b3) && (t.sigl > 0xa763ffff))) {
		EXCEPTION(EX_Invalid);
		/* This is a special case: see sec 16.2.5.1 of the 80486 book */
	      invalid_operand:
		if (control_word & CW_Invalid) {
			/* Produce the QNaN "indefinite" */
			RE_ENTRANT_CHECK_OFF;
			FPU_access_ok(VERIFY_WRITE, d, 10);
			for (i = 0; i < 7; i++)
				FPU_put_user(0, d + i);	/* These bytes "undefined" */
			FPU_put_user(0xc0, d + 7);	/* This byte "undefined" */
			FPU_put_user(0xff, d + 8);
			FPU_put_user(0xff, d + 9);
			RE_ENTRANT_CHECK_ON;
			return 1;
		} else
			return 0;
	} else if (precision_loss) {
		/* Precision loss doesn't stop the data transfer */
		set_precision_flag(precision_loss);
	}

	RE_ENTRANT_CHECK_OFF;
	FPU_access_ok(VERIFY_WRITE, d, 10);
	RE_ENTRANT_CHECK_ON;
	for (i = 0; i < 9; i++) {
		b = FPU_div_small(&ll, 10);
		b |= (FPU_div_small(&ll, 10)) << 4;
		RE_ENTRANT_CHECK_OFF;
		FPU_put_user(b, d + i);
		RE_ENTRANT_CHECK_ON;
	}
	RE_ENTRANT_CHECK_OFF;
	FPU_put_user(sign, d + 9);
	RE_ENTRANT_CHECK_ON;

	return 1;
}

/*===========================================================================*/

/* r gets mangled such that sig is int, sign: 
   it is NOT normalized */
/* The return value (in eax) is zero if the result is exact,
   if bits are changed due to rounding, truncation, etc, then
   a non-zero value is returned */
/* Overflow is signalled by a non-zero return value (in eax).
   In the case of overflow, the returned significand always has the
   largest possible value */
int FPU_round_to_int(FPU_REG *r, u_char tag)
{
	u_char very_big;
	unsigned eax;

	if (tag == TAG_Zero) {
		/* Make sure that zero is returned */
		significand(r) = 0;
		return 0;	/* o.k. */
	}

	if (exponent(r) > 63) {
		r->sigl = r->sigh = ~0;	/* The largest representable number */
		return 1;	/* overflow */
	}

	eax = FPU_shrxs(&r->sigl, 63 - exponent(r));
	very_big = !(~(r->sigh) | ~(r->sigl));	/* test for 0xfff...fff */
#define	half_or_more	(eax & 0x80000000)
#define	frac_part	(eax)
#define more_than_half  ((eax & 0x80000001) == 0x80000001)
	switch (control_word & CW_RC) {
	case RC_RND:
		if (more_than_half	/* nearest */
		    || (half_or_more && (r->sigl & 1))) {	/* odd -> even */
			if (very_big)
				return 1;	/* overflow */
			significand(r)++;
			return PRECISION_LOST_UP;
		}
		break;
	case RC_DOWN:
		if (frac_part && getsign(r)) {
			if (very_big)
				return 1;	/* overflow */
			significand(r)++;
			return PRECISION_LOST_UP;
		}
		break;
	case RC_UP:
		if (frac_part && !getsign(r)) {
			if (very_big)
				return 1;	/* overflow */
			significand(r)++;
			return PRECISION_LOST_UP;
		}
		break;
	case RC_CHOP:
		break;
	}

	return eax ? PRECISION_LOST_DOWN : 0;

}

/*===========================================================================*/

u_char __user *fldenv(fpu_addr_modes addr_modes, u_char __user *s)
{
	unsigned short tag_word = 0;
	u_char tag;
	int i;

	if ((addr_modes.default_mode == VM86) ||
	    ((addr_modes.default_mode == PM16)
	     ^ (addr_modes.override.operand_size == OP_SIZE_PREFIX))) {
		RE_ENTRANT_CHECK_OFF;
		FPU_access_ok(VERIFY_READ, s, 0x0e);
		FPU_get_user(control_word, (unsigned short __user *)s);
		FPU_get_user(partial_status, (unsigned short __user *)(s + 2));
		FPU_get_user(tag_word, (unsigned short __user *)(s + 4));
		FPU_get_user(instruction_address.offset,
			     (unsigned short __user *)(s + 6));
		FPU_get_user(instruction_address.selector,
			     (unsigned short __user *)(s + 8));
		FPU_get_user(operand_address.offset,
			     (unsigned short __user *)(s + 0x0a));
		FPU_get_user(operand_address.selector,
			     (unsigned short __user *)(s + 0x0c));
		RE_ENTRANT_CHECK_ON;
		s += 0x0e;
		if (addr_modes.default_mode == VM86) {
			instruction_address.offset
			    += (instruction_address.selector & 0xf000) << 4;
			operand_address.offset +=
			    (operand_address.selector & 0xf000) << 4;
		}
	} else {
		RE_ENTRANT_CHECK_OFF;
		FPU_access_ok(VERIFY_READ, s, 0x1c);
		FPU_get_user(control_word, (unsigned short __user *)s);
		FPU_get_user(partial_status, (unsigned short __user *)(s + 4));
		FPU_get_user(tag_word, (unsigned short __user *)(s + 8));
		FPU_get_user(instruction_address.offset,
			     (unsigned long __user *)(s + 0x0c));
		FPU_get_user(instruction_address.selector,
			     (unsigned short __user *)(s + 0x10));
		FPU_get_user(instruction_address.opcode,
			     (unsigned short __user *)(s + 0x12));
		FPU_get_user(operand_address.offset,
			     (unsigned long __user *)(s + 0x14));
		FPU_get_user(operand_address.selector,
			     (unsigned long __user *)(s + 0x18));
		RE_ENTRANT_CHECK_ON;
		s += 0x1c;
	}

#ifdef PECULIAR_486
	control_word &= ~0xe080;
#endif /* PECULIAR_486 */

	top = (partial_status >> SW_Top_Shift) & 7;

	if (partial_status & ~control_word & CW_Exceptions)
		partial_status |= (SW_Summary | SW_Backward);
	else
		partial_status &= ~(SW_Summary | SW_Backward);

	for (i = 0; i < 8; i++) {
		tag = tag_word & 3;
		tag_word >>= 2;

		if (tag == TAG_Empty)
			/* New tag is empty.  Accept it */
			FPU_settag(i, TAG_Empty);
		else if (FPU_gettag(i) == TAG_Empty) {
			/* Old tag is empty and new tag is not empty.  New tag is determined
			   by old reg contents */
			if (exponent(&fpu_register(i)) == -EXTENDED_Ebias) {
				if (!
				    (fpu_register(i).sigl | fpu_register(i).
				     sigh))
					FPU_settag(i, TAG_Zero);
				else
					FPU_settag(i, TAG_Special);
			} else if (exponent(&fpu_register(i)) ==
				   0x7fff - EXTENDED_Ebias) {
				FPU_settag(i, TAG_Special);
			} else if (fpu_register(i).sigh & 0x80000000)
				FPU_settag(i, TAG_Valid);
			else
				FPU_settag(i, TAG_Special);	/* An Un-normal */
		}
		/* Else old tag is not empty and new tag is not empty.  Old tag
		   remains correct */
	}

	return s;
}

void frstor(fpu_addr_modes addr_modes, u_char __user *data_address)
{
	int i, regnr;
	u_char __user *s = fldenv(addr_modes, data_address);
	int offset = (top & 7) * 10, other = 80 - offset;

	/* Copy all registers in stack order. */
	RE_ENTRANT_CHECK_OFF;
	FPU_access_ok(VERIFY_READ, s, 80);
	__copy_from_user(register_base + offset, s, other);
	if (offset)
		__copy_from_user(register_base, s + other, offset);
	RE_ENTRANT_CHECK_ON;

	for (i = 0; i < 8; i++) {
		regnr = (i + top) & 7;
		if (FPU_gettag(regnr) != TAG_Empty)
			/* The loaded data over-rides all other cases. */
			FPU_settag(regnr, FPU_tagof(&st(i)));
	}

}

u_char __user *fstenv(fpu_addr_modes addr_modes, u_char __user *d)
{
	if ((addr_modes.default_mode == VM86) ||
	    ((addr_modes.default_mode == PM16)
	     ^ (addr_modes.override.operand_size == OP_SIZE_PREFIX))) {
		RE_ENTRANT_CHECK_OFF;
		FPU_access_ok(VERIFY_WRITE, d, 14);
#ifdef PECULIAR_486
		FPU_put_user(control_word & ~0xe080, (unsigned long __user *)d);
#else
		FPU_put_user(control_word, (unsigned short __user *)d);
#endif /* PECULIAR_486 */
		FPU_put_user(status_word(), (unsigned short __user *)(d + 2));
		FPU_put_user(fpu_tag_word, (unsigned short __user *)(d + 4));
		FPU_put_user(instruction_address.offset,
			     (unsigned short __user *)(d + 6));
		FPU_put_user(operand_address.offset,
			     (unsigned short __user *)(d + 0x0a));
		if (addr_modes.default_mode == VM86) {
			FPU_put_user((instruction_address.
				      offset & 0xf0000) >> 4,
				     (unsigned short __user *)(d + 8));
			FPU_put_user((operand_address.offset & 0xf0000) >> 4,
				     (unsigned short __user *)(d + 0x0c));
		} else {
			FPU_put_user(instruction_address.selector,
				     (unsigned short __user *)(d + 8));
			FPU_put_user(operand_address.selector,
				     (unsigned short __user *)(d + 0x0c));
		}
		RE_ENTRANT_CHECK_ON;
		d += 0x0e;
	} else {
		RE_ENTRANT_CHECK_OFF;
		FPU_access_ok(VERIFY_WRITE, d, 7 * 4);
#ifdef PECULIAR_486
		control_word &= ~0xe080;
		/* An 80486 sets nearly all of the reserved bits to 1. */
		control_word |= 0xffff0040;
		partial_status = status_word() | 0xffff0000;
		fpu_tag_word |= 0xffff0000;
		I387->soft.fcs &= ~0xf8000000;
		I387->soft.fos |= 0xffff0000;
#endif /* PECULIAR_486 */
		if (__copy_to_user(d, &control_word, 7 * 4))
			FPU_abort;
		RE_ENTRANT_CHECK_ON;
		d += 0x1c;
	}

	control_word |= CW_Exceptions;
	partial_status &= ~(SW_Summary | SW_Backward);

	return d;
}

void fsave(fpu_addr_modes addr_modes, u_char __user *data_address)
{
	u_char __user *d;
	int offset = (top & 7) * 10, other = 80 - offset;

	d = fstenv(addr_modes, data_address);

	RE_ENTRANT_CHECK_OFF;
	FPU_access_ok(VERIFY_WRITE, d, 80);

	/* Copy all registers in stack order. */
	if (__copy_to_user(d, register_base + offset, other))
		FPU_abort;
	if (offset)
		if (__copy_to_user(d + other, register_base, offset))
			FPU_abort;
	RE_ENTRANT_CHECK_ON;

	finit();
}

/*===========================================================================*/